Animated widgets and widgets that update information use the most memory.
If you have no service in a location where you normally have coverage, please start by turning your device off and on again. We just want to take care of any other problems first.
There may be situations where the Nokia Lumia 521 does not power on, the phone does not respond to the charger, and/or the Windows Home key blinks on/off while connected to the charger.
The battery has been fully drained and does not have sufficient charge to power on or the battery contacts may be damaged.
Follow the on-screen prompts to complete the OTA update.